Columbia Encyclopedia

Search results

500 results found

carotene

(Encyclopedia)carotene kârˈətēnˌ [key], long-chained, unsaturated hydrocarbon found as a pigment in many higher plants, particularly carrots, sweet potatoes, and leafy vegetables. Carotene is thought to assist...

ammonia

(Encyclopedia)ammonia, chemical compound, NH3, colorless gas that is about one half as dense as air at ordinary temperatures and pressures. It has a characteristic pungent, penetrating odor. Ammonia forms a minute ...

dice, in games and gambling

(Encyclopedia)dice [plural of die], small cubes used in games. They are usually made of ivory, bone, wood, plastic, or similar materials. The six sides are numbered by dots from 1 to 6, so placed that the sum of th...

Early Christian art and architecture

(Encyclopedia)Early Christian art and architecture, works of art exhibiting Christian themes and structures designed for Christian worship created relatively soon after the death of Jesus. Most date from the 4th to...

earth, in geology and astronomy

(Encyclopedia)CE5 A. Cross section of the earth, showing its shells B. Detailed cross section of the crust and upper mantle: The lithosphere consists of the hard rock in the crust and upper mantle, lying above t...

Eden, rivers, England and Scotland

(Encyclopedia)Eden, name of several rivers in England and Scotland. The principal one rises in Cumbria, N England, and flows 65 mi (105 km) NW past Carlisle, into Solway Firth. The Vale of Eden is a rich farming re...

Denali National Park and Preserve

(Encyclopedia)Denali National Park and Preserve dənälˈē [key], in the Alaska Range, S central Alaska; comprising Denali National Park (4,740,912 acres/1,919,398 hectares), est. as Mt. McKinley National Park 191...

Dipper, Big, and Little Dipper

(Encyclopedia)Dipper, Big, and Little Dipper: see Ursa Major and Ursa Minor. ...

Downs, North, and South Downs

(Encyclopedia)Downs, North, and South Downs, parallel ranges of chalk hills, SE England. They rise to 965 ft (294 m) at Leith Hill, Surrey. The North Downs range, extending c.100 mi (160 km) from near Farnham, Surr...

drug addiction and drug abuse

(Encyclopedia)drug addiction and drug abuse, chronic or habitual use of any chemical substance to alter states of body or mind for other than medically warranted purposes. Traditional definitions of addiction, with...